The specific aims of this proposal are divided into three major areas; (1) experiments to continue investigation of those metabolic factors important in the etiology of genetic obesity, specifically to investigate the role of adipose tissue lipoprotein lipase and other metabolic factors in the development of inherited obesity, (2) to develop critieria for distinguishing between exogenously produced animal obesities, (3) to evaluate the role of altered lopoprotein lipase and other metabolic markers in weight loss and weight regain and (4) to establish the feasibility of using lipoprotein lipase and thymidine kinase as exzymatic markers for altered adipase tissue growth. Both in vivo and in vitro techniques, including insulin RIA and electron microscopy will be utilized and physiological, nutritional and pharmacological animal intervention experiments are planned. The long term objectives of this proposal are thus, those which will contribute to our understanding of the pathogenesis of obesity and those which contribute to its diagnosis and management.